| Piston sticks at the top of the cylinder (new | | | | inspect both parts and repair or replace as |
| engine). | | | | required. |
| The piston's tolerance inside the piston chamber is | | | | Car engine running backwards. |
| so tight, there is no room for the piston to slide | | | | This is a common problem, with an easy fix as it |
| to the top. The solution is to heat up the piston | | | | is always caused by user errors. Make sure you |
| chamber with a hair dryer or heat gun. This will | | | | put your RC car on the starter box with the |
| expand the chamber, allowing the piston to glide | | | | correct orientation and that you put your wires |
| smoothly, while maintaining good compression. | | | | on the correct poles of the battery. |
| Nitro engine dies as soon as you pull it off the | | | | Your engine dies while warming up. |
| starter box | | | | The most probable cause of this is a worn piston |
| If your RC car is decently tuned, your problem is | | | | and/or cylinder sleeve. When the engine is cold, |
| probably a loose clutch nut . The clutch nut is | | | | compression is adequate to get it started and run |
| what connects the flywheel to the crankshaft. | | | | nicely. As it warms up the fit between piston and |
| Pressing down your RC car on the starter box | | | | sleeve loosens up as the sleeve expands. If the |
| presses the clutch nut against the fly wheel, | | | | fit is bad enough, your fuel can exit the cylinder |
| creating the spin that gets your nitro started. | | | | above the piston. As the engine gets warmer, this |
| However, if your clutch nut is loose from wear | | | | effect gets worse until the engine eventually stalls. |
| and tear or impacts, it won't have the proper | | | | You'll need to replace the engine or, if you like |
| mesh it needs to keep the car running once you | | | | working on this kind of thing, the piston and |
| have removed your vehicle from the starter box. | | | | sleeve. |
| To see if you have a loose clutch nut, look for | | | | Your roto-start or pullstart nitro won't start. |
| the fly wheel spinning on it's own. If it does, you | | | | Your one-way bearing may not be catching on |
| need to remove the engine and tighten or replace | | | | the crank shaft. This can happen if it is extremely |
| the clutch nut. | | | | dirty and you can clean it , let it dry overnight, |
| Engine stalls when car put on the ground. | | | | and re-install it. |
| A frozen clutch-bell bearing or broken | | | | Your engine speed increases while idling. |
| clutch-retainer spring is the most likely culprit. The | | | | Highly probable that the low speed needle on the |
| engine stalls because the clutch is engaged when | | | | engine is set too lean . A good confirmatory test |
| the engine is idling. When you put the car on the | | | | is to pinch the fuel line and time how long the |
| ground the engine croaks as it is not running fast | | | | engine runs. If much less than five seconds it's |
| enough to move the car. The retainer spring or | | | | too lean, if much longer than 5 seconds, it's too |
| clutch bell bearing are forcing the clutch to be | | | | rich. |
| engaged when it shouldn't be. You'll need to | | | | |